Buprenorphine acts as a mixed agonist/antagonist and it is an important treatment option for opiate addiction and analgesia.
The conventional synthetic route used world-wide to prepare buprenorphine utilizes thebaine as the starting material.

Through a series of chemical reactions, thebaine is converted into nor-buprenorphine, the immediate precursor to buprenorphine. The final step adds a cyclopropyl methyl group to the nitrogen to form buprenorphine from nor-buprenorphine.
An outline of the conventional series of reactions from thebaine to buprenorphine follows:                1. Reaction of thebaine with methyl vinyl ketone to form the 4+2 reaction product.        2. Hydrogenation of the carbon-carbon double bond.        3. Addition of a tertiary butyl group via a Grignard Reaction.        4. An N-demethylation, via a two step reaction sequence.        5. An O-demethylation reaction and an N-cyano hydrolysis.        6. Addition of the cyclopropyl methyl group to form buprenorphine.        
A drawback of this conventional production scheme is that the O-demethylation step is considered a low to moderate yield transformation. There is therefore a need for a norbuprenorphine/buprenorphine production scheme that does not include an O-demethylation step.